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81.
Kageyama D Anbutsu H Watada M Hosokawa T Shimada M Fukatsu T 《Applied and environmental microbiology》2006,72(10):6667-6673
Male-killing phenotypes are found in a variety of insects and are often associated with maternally inherited endosymbiotic bacteria. In several species of Drosophila, male-killing endosymbionts of the genus Spiroplasma have been found at low frequencies (0.1 to 3%). In this study, spiroplasma infection without causing male-killing was shown to be prevalent (23 to 66%) in Japanese populations of Drosophila hydei. Molecular phylogenetic analyses showed that D. hydei was infected with a single strain of spiroplasma, which was closely related to male-killing spiroplasmas from other Drosophila species. Artificial-transfer experiments suggested that the spiroplasma genotype rather than the host genotype was responsible for the absence of the male-killing phenotype. Infection densities of the spiroplasma in the natural host, D. hydei, and in the artificial host, Drosophila melanogaster, were significantly lower than those of the male-killing spiroplasma NSRO, which was in accordance with the hypothesis that a threshold infection density is needed for the spiroplasma-induced male-killing expression. 相似文献
82.
Autophagy is an intracellular bulk degradation system. We established mouse fibroblast lines coupling the Tet-off system with an Atg5(-/-) mouse embryonic fibroblast line to artificially regulate autophagic ability. In the presence of doxycycline (Dox), Atg5 expression was completely suppressed and these cells were autophagy-defective. After removal of Dox, autophagic ability was restored within 6h. Very low levels of Atg5 could induce an autophagy competent state. We applied this novel system to examine the contribution of autophagy to controlling cell size. Cell size reduction in response to starvation was significantly inhibited in cells unable to undergo autophagy. The generated cell lines will be useful reagents for future mechanistic studies into the regulation and physiologic significance of autophagy. 相似文献
83.
Y Wang A Nakajima K Hosokawa AB Soliev I Osaka R Arakawa K Enomoto 《Bioscience, biotechnology, and biochemistry》2012,76(6):1229-1232
Pseudoalteromonas sp. 1020R, isolated from the Pacific coast of Japan, produces prodigiosin family pigments. Structural analysis indicated that these are prodigiosin (2-methyl-3-pentyl-prodiginine) and three other prodigiosin congeners which differ only in the lengths of the alkyl side chains. These compounds exhibited different extents of cytotoxicity against U937 leukemia cells, and cell death was accompanied by typical features of apoptosis. 相似文献
84.
Koeda S Hosokawa M Kang BC Tanaka C Choi D Sano S Shiina T Doi M Yazawa S 《Journal of plant research》2012,125(1):137-145
Temperature is one of the most important environmental factors that influence plant growth and development. Recent studies
imply that plants show various responses to non-extreme ambient temperatures. Previously, we have found that a pepper cultivar
cv. Sy-2 (Capsicum chinense) shows developmental defects at temperatures below 24°C. In this study, to gain new insights into the temperature sensitivity
of cv. Sy-2, temperature-sensitive genes were screened using microarray techniques. At restrictive temperature of 20°C, almost
one-fourth of the 411 up-regulated genes were defense related or predicted to be defense related. Further expression analyses
of several defense-related genes showed that defense-related genes in cv. Sy-2 were constitutively expressed at temperatures
below 24°C. Moreover, accumulation of high level of salicylic acid (SA) in cv. Sy-2 grown at 20°C suggests that the defense
response is activated in the absence of pathogens. To confirm that the defense response is induced in cv. Sy-2 below 24°C,
we evaluated the resistance to biotrophic bacterial pathogen Xanthomonas campestris pv. vesicatoria and necrotrophic fungal pathogen Cercospora capsici. Cv. Sy-2 showed enhanced resistance to X. campestris pv. vesicatoria, but not to C. capsici. 相似文献
85.
Fucoxanthin (Fx) isolated from Undaria pinnatifida suppresses the development of hyperglycemia and hyperinsulinemia of diabetic/obese KK-A(y) mice after 2 weeks of feeding 0.2% Fx-containing diet. In the soleus muscle of KK-A(y) mice that were fed Fx, glucose transporter 4 (GLUT4) translocation to plasma membranes from cytosol was promoted. On the other hand, Fx increased GLUT4 expression levels in the extensor digitorum longus (EDL) muscle, although GLUT4 translocation tended to increase. The expression levels of insulin receptor (IR) mRNA and phosphorylation of Akt, which are in upstream of the insulin signaling pathway regulating GLUT4 translocation, were also enhanced in the soleus and EDL muscles of the mice fed Fx. Furthermore, Fx induced peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α), which has been reported to increase GLUT4 expression, in both soleus and EDL muscles. These results suggest that in diabetic/obese KK-A(y) mice, Fx improves hyperglycemia by activating the insulin signaling pathway, including GLUT4 translocation, and inducing GLUT4 expression in the soleus and EDL muscles, respectively, of diabetic/obese KK-A(y) mice. 相似文献
86.
Eisuke Kato Michitsugu Yama Ryo Nakagomi Toshiro Shibata Keizo Hosokawa Jun Kawabata 《Bioorganic & medicinal chemistry letters》2012,22(20):6410-6412
Filipendula kamtschatica is a plant utilized as a traditional medicine by Ainu people in Japan, but its chemical constituents are not much studied. Pancreatic lipase inhibitors are a promising tool for the treatment of obesity. We searched for natural lipase inhibitors from F. kamtschatica and two new compounds were isolated along with the known flavonoid glycoside. The structure elucidation of new compounds revealed these two to be 2-O-caffeoyl-4-O-galloyl-l-threonic acid and 3-O-caffeoyl-4-O-galloyl-l-threonic acid, which can be recognized as a pancreatic lipase’s substrate-like structure. The isolated compounds all showed an inhibitory activity against porcine pancreatic lipase and one of the isomer, 3-O-caffeoyl-4-O-galloyl-l-threonic acid, possessed the most potent activity with IC50 value showing an order lower value compared to others. The substrate-like structure of the new compounds seemed to be important for their activity. 相似文献
87.
M Sakamoto R Nishimura T Irako D Tsujino K Ando K Utsunomiya 《Cardiovascular diabetology》2012,11(1):92
ABSTRACT: BACKGROUND: No previous studies have compared the DPP-4 inhibitors vildagliptin and sitagliptin in terms of blood glucose levels using continuous glucose monitoring (CGM) and cardiovascular parameters. METHODS: Twenty patients with type 2 diabetes mellitus were randomly allocated to groups who received vildagliptin then sitagliptin, or vice versa. Patients were hospitalized at 1 month after starting each drug, and CGM was used to determine: 1) mean (+/- standard deviation) 24-hour blood glucose level, 2) mean amplitude of glycemic excursions (MAGE), 3) fasting blood glucose level, 4) highest postprandial blood glucose level and time, 5) increase in blood glucose level after each meal, 6) area under the curve (AUC) for blood glucose level [greater than or equal to]180 mg/dL within 3 hours after each meal, and 7) area over the curve (AOC) for daily blood glucose level <70 mg/dL. Plasma glycosylated hemoglobin (HbA1c), glycoalbumin (GA), 1,5-anhydroglucitol (1,5AG), immunoreactive insulin (IRI), C-peptide immunoreactivity (CPR), brain natriuretic peptide (BNP), and plasminogen activator inhibitor-1 (PAI-1) levels, and urinary CPR levels, were measured. RESULTS: The mean 24-hour blood glucose level was significantly lower in patients taking vildagliptin than sitagliptin (142.1 +/- 35.5 vs. 153.2 +/- 37.0 mg/dL; p = 0.012). In patients taking vildagliptin, MAGE was significantly lower (110.5 +/- 33.5 vs. 129.4 +/- 45.1 mg/dL; p = 0.040), the highest blood glucose level after supper was significantly lower (206.1 +/- 40.2 vs. 223.2 +/- 43.5 mg/dL; p = 0.015), the AUC ([greater than or equal to]180 mg/dL) within 3 hours was significantly lower after breakfast (484.3 vs. 897.9 mg/min/dL; p = 0.025), and urinary CPR level was significantly higher (97.0 +/- 41.6 vs. 85.2 +/- 39.9 mug/day; p = 0.008) than in patients taking sitagliptin. There were no significant differences in plasma HbA1c, GA, 1,5AG, IRI, CPR, BNP, or PAI-1 levels between patients taking vildagliptin and sitagliptin. CONCLUSIONS: CGM showed that mean 24-hour blood glucose, MAGE, highest blood glucose level after supper, and hyperglycemia after breakfast were significantly lower in patients with type 2 diabetes mellitus taking vildagliptin than those taking sitagliptin. There were no significant differences in BNP and PAI-1 levels between patients taking vildagliptin and sitagliptin. Trial registration UMIN000007687 KEYWORDS: Vildagliptin; Sitagliptin; Continuous glucose monitoring (CGM); Brain natriuretic peptide (BNP); plasminogen activator inhibitor-1 (PAI-1). 相似文献
88.
Y Maruyama A Kawano S Okamoto T Ando Y Ishitobi Y Tanaka A Inoue J Imanaga M Kanehisa H Higuma T Ninomiya J Tsuru H Hanada J Akiyoshi 《PloS one》2012,7(7):e39375
Background
Cortisol is an essential hormone in the regulation of the stress response along the HPA axis, and salivary cortisol has been used as a measure of free circulating cortisol levels. Recently, salivary alpha-amylase (sAA) has also emerged as a novel biomarker for psychosocial stress responsiveness within the sympathetic adrenomedullary (SAM) system.Principal Findings
We measured sAA and salivary cortisol in healthy volunteers after exposure to the Trier Social Stress Test (TSST) and electric stimulation stress. One hundred forty-nine healthy volunteers participated in this study. All subjects were exposed to both the TSST and electric stimulation stress on separate days. We measured sAA and salivary cortisol levels three times immediately before, immediately after, and 20 min after the stress challenge. The State (STAI-S) and Trait (STAI-T) versions of the Spielberger Anxiety Inventory test and the Profile of Mood State (POMS) tests were administered to participants before the electrical stimulation and TSST protocols. We also measured HF, LF and LF/HF Heart Rate Variability ratio immediately after electrical stimulation and TSST exposure. Following TSST exposure or electrical stimulation, sAA levels displayed a rapid increase and recovery, returning to baseline levels 20 min after the stress challenge. Salivary cortisol responses showed a delayed increase, which remained significantly elevated from baseline levels 20 min after the stress challenge. Analyses revealed no differences between men and women with regard to their sAA response to the challenges (TSST or electric stimulations), while we found significantly higher salivary cortisol responses to the TSST in females. We also found that younger subjects tended to display higher sAA activity. Salivary cortisol levels were significantly correlated with the strength of the applied electrical stimulation.Conclusions
These preliminary results suggest that the HPA axis (but not the SAM system) may show differential response patterns to distinct kinds of stressors. 相似文献89.
90.
Hosokawa T Tsuchiya K Sato I Takeyama N Ueda S Tagawa Y Kimura KM Nakamura I Wu G Sakudo A Casalone C Mazza M Caramelli M Takahashi H Sata T Sugiura K Baj A Toniolo A Onodera T 《Biochemical and biophysical research communications》2008,366(3):657-663
A monoclonal antibody (mAb) panel to bovine prion protein (PrP) was studied by immunoblotting and immunohistochemistry for scrapie and bovine spongiform encephalopathy. A mAb panel recognized both normal (PrPC) and abnormal (PrPSc) isoforms of PrP in murine, ovine and bovine brain tissues. Interestingly, an anti-bovine PrP mAb, 1D12, prepared by immunizing PrP gene-knockout mice with a synthetic polypeptides corresponding to codons 153-166 of the bovine PrP gene showed novel patterns of reactivity for prion-uninfected neuronal cells. An enzyme-linked immunosorbent assay-mapping of the mAb epitopes resulted in a reaction of monoclonal 1D12 to YEDRY and M corresponding to amino acids 156-160 and 165 of bovine PrP. Several patterns of bovine PrPC distribution in PrP-deficient neuronal cells (HpL3-4) transfected with bovine PrP were observed after different fixation methods. Stained cell surface was observed after formalin fixation by immunofluorescent assay of 1D12 with confocal microscopy, whereas granules in nucleus were stained after acetone fixation. No reactivity in the nucleus was observed to HpL3-4, or HpL3-4mPrP cells expressing mouse PrP. This is the first paper that has reported the detection of the PrPC at both cell surface and nuclei of prion-uninfected cell line. 相似文献